The present invention relates to a method and apparatus for supporting a paving vehicle on an inclined surface. Asphalt finishers, steel rollers and tire rollers are all typical paving vehicles.
Also, the invention relates to a method and apparatus for paving a three-dimensional curved surface and, more particularly, to a system for uniformly laying a paving material such as asphalt onto the three-dimensional curved surface.
A slope face such as a test course for automobiles is paved by laying asphalt on the slope face with an asphalt finisher and then compacting the asphalt with a steel roller, tire roller, or the like. These steps are well known. For example, as shown in FIG. 1, an asphalt finisher C, a steel roller D, and a tire roller E, are supported by wires W from anchor vehicles B which run on a top end portion A. The asphalt finisher C, steel roller D, and the tire roller E run on the slope face F, thereby paving the surface of the inclined slope face. In the diagram, T denotes a dump truck and R indicates a machine for laterally transporting a paving material such as asphalt or concrete.
When paving machines on an inclined surface are supported by wires, an improper supporting method can result in nonuniformity of the paved surface and a deterioration of its working quality. However, hitherto, a satisfactory countermeasure has not been realized. For example, FIG. 2, illustrates the case where a paving machine M is supported on the inclined surface F by the wire W from an anchor vehicle B. A fixed point P of the wire is offset by a distance l from the position of the center of gravity G of the paving machine M, so the paving machine is subjected to a moment M=T.multidot.l which generates uneven loads in the wheels H and adversely influences the finished state of the paved roadbed.
On the other hand, as shown in FIG. 3, when the fixed point P of the wire is located on the extension line of the center of gravity G, no problem will be caused if an angle .theta. between the supporting direction of the wire W and the inclined surface F coincides with this direction. However, if the supporting angle of the wire increases by an angle .alpha. greater than the angle .theta. during running, the component of force J=T sin .alpha. occurs. The loads of the right and left wheels H of the paving machine M are unbalanced. The wheel with a smaller load can slip and the paved surface becomes rough. In the worst case, the paving apparatus M cannot run. The working efficiency deteriorates and the paving quality deteriorates.
In levees and similar structures, where the angle of inclination of the inclined surface is constant, the problems of unbalanced wheel loads can be avoided by presetting the supporting direction of the wire. However, as shown in FIG. 4, when the slope face F is curved as in an automotive test course, the inclination continuously changes in directions which are transverse and longitudinal of the test course. Accordingly, the foregoing problems will occur if some countermeasures are not taken.
Asphalt finishers for finishing curved roadbed surfaces have been disclosed in the Official Gazette of Japanese patent publication No. 38530/78 and the Official Gazette of Japanese utility model laid-open publication No. 85105/80. However, these prior devices have shortcomings in the respect that manual operation is needed to pave surfaces which have complicated curvatures. This requires skilled and experienced operators in order to achieve the desired degree of accuracy.
It is an object of the present invention to provide an apparatus for supporting a paving machine which avoids the foregoing problems, even when the inclination angle of the slope face changes, as is the case in an automotive test course.
It is also an object of the invention to provide a system for paving a three-dimensional curved surface which can provide high accuracy without manual operation.